merge: apply non-interactive working dir updates in parallel
This has a big effect on the performance of working dir updates.
Here are the results of update from null to the given rev in several
repos, on a Linux 3.2 system with 32 cores running ext4, with the progress
extension enabled.
repo rev plain parallel speedup
hg
7068089c95a2 0.9 0.3 3
mozilla-central
fe1600b22c77 42.8 7.7 5.5
linux-2.6
9ef4b770e069 31.4 4.9 6.4
Verify that pending changesets are seen by pretxn* hooks but not by other
processes that access the destination repo while the hooks are running.
The hooks (python and external) both reject changesets after some think time,
during which another process runs pull. Each hook creates a file ('notify') to
indicate to the controlling process that it is running; the process removes the
file to indicate the hook can terminate.
init env vars
$ d=`pwd`
$ maxwait=20
utility to run the test - start a push in the background and run pull
$ dotest() {
> rm -f notify
> printf 'push '; hg -R child-push tip --template '{node}\n'
> hg -R child-push -q push > push.out 2>&1 &
>
> # wait for hook to create the notify file
> i=$maxwait
> while [ ! -f notify -a $i != 0 ]; do
> sleep 1
> i=`expr $i - 1`
> done
>
> # run pull
> hg -R child-pull -q pull
> rc=$?
>
> # tell hook to finish; notify should exist.
> rm notify
> wait
>
> cat push.out
> printf 'pull '; hg -R child-pull tip --template '{node}\n'
> return $rc
> }
python hook
$ cat <<EOF > reject.py
> import os, time
> from mercurial import ui, localrepo
> def rejecthook(ui, repo, hooktype, node, **opts):
> ui.write('hook %s\\n' % repo['tip'].hex())
> # create the notify file so caller knows we're running
> fpath = os.path.join('$d', 'notify')
> f = open(fpath, 'w')
> f.close()
> # wait for ack - caller should delete the notify file
> i = $maxwait
> while os.path.exists(fpath) and i > 0:
> time.sleep(1)
> i -= 1
> return True # reject the changesets
> EOF
external hook
$ cat <<EOF > reject.sh
> printf 'hook '; hg tip --template '{node}\\n'
> # create the notify file so caller knows we're running
> fpath=$d/notify
> touch \$fpath
> # wait for ack - caller should delete the notify file
> i=$maxwait
> while [ -f \$fpath -a \$i != 0 ]; do
> sleep 1
> i=\`expr \$i - 1\`
> done
> exit 1 # reject the changesets
> EOF
create repos
$ hg init parent
$ hg clone -q parent child-push
$ hg clone -q parent child-pull
$ echo a > child-push/a
$ hg -R child-push add child-push/a
$ hg -R child-push commit -m a -d '1000000 0'
test python hook
$ cat <<EOF > parent/.hg/hgrc
> [extensions]
> reject = $d/reject.py
> [hooks]
> pretxnchangegroup = python:reject.rejecthook
> EOF
$ dotest
push 29b62aeb769fdf78d8d9c5f28b017f76d7ef824b
hook 29b62aeb769fdf78d8d9c5f28b017f76d7ef824b
transaction abort!
rollback completed
abort: pretxnchangegroup hook failed
pull 0000000000000000000000000000000000000000
test external hook
$ cat <<EOF > parent/.hg/hgrc
> [hooks]
> pretxnchangegroup = sh $d/reject.sh
> EOF
$ dotest
push 29b62aeb769fdf78d8d9c5f28b017f76d7ef824b
hook 29b62aeb769fdf78d8d9c5f28b017f76d7ef824b
transaction abort!
rollback completed
abort: pretxnchangegroup hook exited with status 1
pull 0000000000000000000000000000000000000000